Initialize callbacks to null.
Initialize callbacks to null.

rmhartog/thrift,rmhartog/thrift,rmhartog/thrift,rmhartog/thrift,rmhartog/thrift,rmhartog/thrift,rmhartog/thrift,rmhartog/thrift,rmhartog/thrift,rmhartog/thrift,rmhartog/thrift